Dispensers for fibrin glue should be easy to handle, non clogging, and precise in their ability to place and meter the fibrin glue at the desired site. To date, all prior art dispensers have been deficient in one or more of the above areas. Because fibrinogen, which is used to produce the fibrin glue is a relatively precious commodity, especially when the fibrinogen is derived autologously, it is imperative that the maximum efficiency possible be experienced when dispensing fibrin glue.
Precise metering has been the bane of devices which dispense fibrin glue. Metering implies that both the precise quantity of fibrin glue will be dispensed and delivered strategically to the appropriate site. Because the glue can obstruct passageways, volume variations which lead to clogging have been a recurring problem.
Impediments that exacerbate the foregoing problems include lack of an ergonomically designed dispensing tool which would facilitate usage in a natural, intuitive way. If the dispensing tool cannot be conveniently grasped, the product being delivered is less likely to be accurately deployed either to the right site or in the right amount.
Another vexing, recurring problem in mixing two component compounds involves the strategic blending of the two components at the appropriate location. A chemical process is associated with mixing the two components. Timing and location are critical. Otherwise, the chemical reaction will likely occur at an unwanted location at an unwanted time. Since fibrin glue is formed substantially immediately upon the contact of thrombin with fibrinogen, and because fibrin glue sets up almost immediately upon its formation, clogging of a dispensing tool can occur. During a surgical procedure, when fibrin glue is used to stem the flow of blood, malfunctions of a fibrin glue delivering tool can have adverse consequences. One corollary to the problem of clogging involves the fact that the thrombin and fibrinogen are typically loaded into the dispensing device with syringes. Should a clog occur, either the dispensing instrumentality has to be cleaned or replaced under aseptic conditions since the fibrinogen and thrombin earmarked for that procedure should be salvaged if at all possible.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these citations teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as especially claimed and as set forth in greater detail hereinafter.
______________________________________ PATENT NO. ISSUE DATE INVENTOR ______________________________________ 4,874,368 October 17, 1989 Miller, et al. 5,104,375 April 14, 1992 Wolf, et al. 5,116,315 May 26, 1992 Capozzi, et al. 5,240,146 August 31, 1993 Smedley, et al. 5,253,785 October 19, 1993 Haber, et al. 5,271,527 December 21, 1993 Haber, et al. 5,286,258 February 15, 1994 Haber, et al. 5,290,259 March 1, 1994 Fischer 5,314,412 May 24, 1994 Rex 5,318,524 June 7, 1994 Morse, et al. 5,322,510 June 7, 1994 Lindner, et al. 5,330,079 July 19, 1994 Keller 5,330,974 July 19, 1994 Pines, et al. 5,368,563 November 29, 1994 Looneman, et al. 5,378,233 January 3, 1995 Haber, et al. 5,405,607 April 11, 1995 Epstein 5,423,752 June 13, 1995 Haber, et al. 5,464,396 November 7, 1995 Barta, et al. 5,474,540 December 12, 1995 Miller, et al. 5,505,704 April 9, 1996 Pawelka, et al. ______________________________________